Class istream

namespace std
{
  class istream : public class ios_base
  {
    // overloads of input operator
    friend istream& operator >> (istream& , char);
    friend istream& operator >> (istream& , int);
    friend istream& operator >> (istream& , long);
    friend istream& operator >> (istream& , unsigned char);
    friend istream& operator >> (istream& , unsigned int);
    friend istream& operator >> (istream& , unsigned long);
    friend istream& operator >> (istream& , float);
    friend istream& operator >> (istream& , double);
    friend istream& operator >> (istream& , long double);
    friend istream& operator >> (istream& , char* );
    ...
    public:
      // methods to access next element in stream
      char get ();  
      void get (char&);
      char peek ();
      ...
  } cin;  // predefined object
} // namespace std